removing *.o file so that C-xC-s surely works.

Check.hs

@@ -16,11 +16,16 @@ import System.Process
 
 checkSyntax :: Options -> String -> IO String
 checkSyntax opt file = do
-    makeDirectory (outDir opt)
+    let outdir = outDir opt
+        outfile = outFile opt
+        objfile = objectFile outdir file
+    makeDirectory outdir
+    exist <- doesFileExist objfile
+    when exist $ removeFile objfile
 #if __GLASGOW_HASKELL__ >= 611
-    (_,_,herr,_) <- runInteractiveProcess (ghc opt) ["--make","-Wall","-fno-warn-unused-do-bind",file,"-outputdir","dist/flymake","-o","dist/flymake/a.out","-i..","-i../..","-i../../..","-i../../../..","-i../../../../.."] Nothing Nothing
+    (_,_,herr,_) <- runInteractiveProcess (ghc opt) ["--make","-Wall","-fno-warn-unused-do-bind",file,"-outputdir",outdir,"-o",outfile,"-i..","-i../..","-i../../..","-i../../../..","-i../../../../.."] Nothing Nothing
 #else
-    (_,_,herr,_) <- runInteractiveProcess (ghc opt) ["--make","-Wall",file,"-outputdir","dist/flymake","-o","dist/flymake/a.out","-i..","-i../..","-i../../..","-i../../../..","-i../../../../.."] Nothing Nothing
+    (_,_,herr,_) <- runInteractiveProcess (ghc opt) ["--make","-Wall",file,"-outputdir",outdir,"-o",outfile,"-i..","-i../..","-i../../..","-i../../../..","-i../../../../.."] Nothing Nothing
 #endif
     hSetBinaryMode herr False
     refine <$> hGetContents herr
@@ -51,3 +56,6 @@ makeDirectory dir = makeDirectoryRecur $ normalise dir
       unless exist $ do
           makeDirectoryRecur par
           createDirectory cur
+
+objectFile :: FilePath -> FilePath -> FilePath
+objectFile dir hsfile = dir </> replaceExtension hsfile ".o"

GHCMod.hs

@@ -28,7 +28,8 @@ defaultOptions = Options { convert = toPlain
                          , ghc     = "ghc"
                          , ghci    = "ghci"
                          , ghcPkg  = "ghc-pkg"
-                         , outDir  = "dist/flymake"
+                         , outDir  = outputDir
+                         , outFile = outputFile
                          }
 
 argspec :: [OptDescr (Options -> Options)]

Param.hs

@@ -1,9 +1,16 @@
 module Param where
 
-data Options   = Options { convert :: [String] -> String
+data Options = Options {
+    convert :: [String] -> String
   , ghc     :: FilePath
   , ghci    :: FilePath
   , ghcPkg  :: FilePath
   , outDir  :: FilePath
+  , outFile :: FilePath
   }
 
+outputDir :: String
+outputDir = "dist/flymake"
+
+outputFile :: String
+outputFile = "dist/flymake/a.out"